Save battery on unchanging location.
Uses 2-part detection:
1) DetectUnchangingLocation is used to determine if the user has not
moved in 2 minutes, then the ScanManager pauses (this is a low power
state)
2) When the MotionSensor detects movement (which uses very low power
sensors to do so), start scanning again.

Also worth noting, the notification text changes when paused, and the
map view shows a paused message also.

- MapLocationListener will use the network listener until the GPS
kicks in.
Wrap unregisterReceiver in try/catch
Added developer options to control the motions sensing
Fixed a bug, time window was in seconds, not ms.
Added gui log messages to indicate no gps timeout, or lack of movement distance
Merge pull request #1270 from garvankeeley/motion-detection

Battery-saving mode (by pausing GPS and scanners) on unchanging location.